MS3 on 3 cylinder Motorcycle

[R3Hoon]

Hi all, been about 10 years since I've worked with megasquirt. I had one of the first MSnS Extras running a custom Turbo motor back in 2004, and, now I've reached a point in a project where a full standalone is called for again.

The vehicle in question is a 2014 Triumph Rocket III Roadster. It has significant engine internal work done and the stock ECU is now the limiting factor, it only allows a peak RPM of 7000, I need to spin the motor to at least 8000 if not 9000 to make full use of the much larger cams.

From what I have seen its a 24-2 trigger wheel, no cam sensor, CDI system. I want sequential injection. The ignition setup uses 3 leads to coils which fire two plugs each simultaneously. There are 3 injectors wich are high resistance.

The IAT and coolant sensors I'll have to replace with GM versions, no big deal. The stock MAP sensor is 1 BAR, just fine, and uses a 0-5 volt linear output as far as I can tell. TPS is a 0-5v system using a linear sensor output.

Is there anything here that you guys can see which will cause any issues? As far as I can tell it should be a very straight forward conversion to MS3 from the stock ECU.

The only sticking point I see that might come up is the IACV. It uses a stepper motor to control idle and resist stalling.

Can MS3 provide sequential injection for a 3 cylinder as described and control the stepper motor natively or am I looking at custom circuitry like I had to do last time using MS?

[grom_e30]

i believe for a 3 cylinder you will also need the cam sensor as well if the 24-2 is mounted on the crank.

[ChristianK]

You didn't need a cam signal. It works fine with 6-zyl. wasted spark. ;-)

[racingmini_mtl]

You didn't need a cam signal. It works fine with 6-zyl. wasted spark. ;-)

Yeah but you have to change the wiring to a different firing order. It won't fire in the ABC order but ACB since it's firing every 120 degrees instead of every 240 degrees.

Jean

[grom_e30]

I want sequential injection

i assume you need the cam signal for sequential injection.

[motthomas]

Why can't you use the stock IAT & CLT sensors? The service manual should provide you with a 3 point cal and they are likely to be a good bit tidier than the GM units which are very pretty bulky for a bike application.